KISTI Demonstrates Quantum-key Relay System at ECOC 2025, Selected as the Only Asian Demo for Two Conseive Years

- Demonstration of secure quantum key delivery across independent networks 

- Expanding interoperability beyond vendor and operator boundaries

□ The Quantum Network Research Center of the Korea Institute of Science and Technology Information (KISTI, President Lee Sik) showcased its Smart Quantum-key Relay System (SQRS) at the European Conference on Optical Communication 2025 (ECOC 2025), held in Copenhagen, Denmark, on September 30.

□ ECOC is Europe’s largest academic conference on optical communications, where leading research institutions and industry players from around the world present their latest technologies and findings. Among this year’s entries, only seven demonstrations were selected, and KISTI’s team was the sole representative from Asia—for the second conseive year, reaffirming its global leadership in quantum communication research.

□ The SQRS enables secure and intelligent quantum key delivery between independently operated Quantum Key Distribution (QKD) networks. Unlike conventional dependent structures, SQRS is designed to allow flexible and efficient key exchange between vendors and operator networks without the risk of information leakage. Notably, its ability to dynamically select the optimal encryption method according to each user’s security requirements and available quantum key capacity minimizes transmission latency and enhances overall operational efficiency—making it a core technology for scalable quantum communication networks.

□ Wonhyuk Lee, Director of KISTI’s Quantum Network Research Center, stated, “SQRS is a key technology that enables the practical expansion of quantum communication networks. We expect this demonstration to further strengthen research collaboration with domestic and international institutions in the quantum communication field.”

□ The study’s lead author, Kyuseok Sim, Senior Research Engineer at the same center, added, “Through SQRS, both service providers and users can benefit from a more efficient and interoperable ecosystem. We anticipate that this technology will contribute to promoting collaboration, reducing costs, and accelerating innovation within the global quantum communication industry.”

Researchers at KISTI’s Quantum Network Research Center

  (From left: Wonhyuk Lee (Director), Chankyun Lee, Kyuseok Sim, and Jubong Kim)

Process of the Smart Quantum-key Relay System (SQRS)